The present invention relates to methods of compressing, transferring and reproducing data such as video data and audio data (musical performance data).
Known hand-held communications devices such as cellular telephones have a function of melody signaling for incoming calls using a part of music of several kinds in addition to monotonous melody.
These melodies are pre-stored on hand-held communications devices (terminals). In addition, for users who want to use popular songs for melody signaling, such songs are downloaded to user hand-held communications devices from a database provided in a server.
The downloaded data are reproduced by reproducing circuitry or software stored in ROM, RAM or memory device built in the hand-held communications devices.
As for melody signaling, MIDI (Musical Instrument Digital Interface) data is better than PCM audio data (musical performance data) for data amount. However, even though MIDI is used, whole song data is required when hand-held communications devices such as cellular telephones are used as audio playback systems. But the transmission rate is limited and the data amount for each communications device is limited so that everyone can use the services.
MIDI data is also used for other entertainment systems such as a xe2x80x9ckaraokexe2x80x9d system, a machine that plays recorded music which people can sing along. A xe2x80x9ckaraokexe2x80x9d system requires necessary data not only whole song data but also character data for displaying lyrics of recorded xe2x80x9ckaraokexe2x80x9d music and background image data, for example.
This results in a long downloading time and shortage of storage capacity of the internal memory device a hand-held communications device due to increasing the offer data for the multi-media application and so on in the total data amount even though a data amount is small for MIDI data.
MIDI music-performance data is generally written as a standard MIDI file (called SMF hereinafter). However, due to relatively large size for SMF, special formats for melody signaling for incoming calls such as MFi, SMAF and Compact MIDI Formats are used instead.
Compression ratios for these special formats are, however, almost half that for SMF, and hence improvement in compression ratio is necessary.
Melody signaling data for incoming calls is protected against unauthorized use in a closed network such as i-mode, provided by a Japanese cellular telephone company, for cellular telephones to access Internet.
However, standard data SMFs formed and provided by contents makers at high cost could be used by unauthorized persons when used for melody signaling in a new service in which melody signaling data can be downloaded via an open network in future.
In other words, standard data SMFs are convenient for ordinary users, and there are various types of off-the-shelf MIDI application softwares. It is thus convenient for ordinary users and contents makers to distribute standard data SMFs compressed as they are, via an open network.
A purpose of the present invention is to provide methods of data compression, transfer and reproduction that achieve decrease in data amount for music-performance data files and protection of the files against unauthorized use.
The present invention provides a data compression method including the following steps. Music-performance data is separated into at least note-number data, musical note-velocity data, musical note-length data and other necessary data. A primary encoded code is formed in which the note-number data, the musical note-velocity data, the musical note-length data and the other necessary data are arranged in different data fields. The primary encoded code and a playback player are compressed, the playback player being formed in software having a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data, thus forming a first secondary encoded code for the primary encoded code and a second secondary encoded code for the playback player.
Moreover, the present invention provides a data decompression method including the following steps. A first secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. A second secondary encoded code is decoded into a playback player formed in software having a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.
Furthermore, the present invention provides a method of decompressing a first secondary encoded code and a second secondary encoded code. The method includes the following steps. The first secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. The second secondary encoded code is decoded into a playback player formed in software having a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.
Furthermore, the present invention provides a decompression method including the following steps. A combined code is separated into a lyric data and a first secondary encoded code. The first secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. A second secondary encoded code is decoded into a playback player formed in software having a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.
Moreover, the present invention provides a method of decompressing a combined code of a lyric data and a first secondary encoded code, and also decompressing a second secondary encoded code. The method includes the following steps. The combined code is separated into the lyric data and the first secondary encoded code. The first secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. The second secondary encoded code is decoded into a playback player formed in software having a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.
Moreover, the present invention provides a data compression method including the following steps. Music-performance data is separated into at least note-number data, musical note-velocity data, musical note-length data and other necessary data. A primary encoded code is formed in which the note-number data, the musical note-velocity data, the musical note-length data and the other necessary data are arranged in different data fields. The primary encoded code is compressed into a secondary encoded code. A playback player is compressed that is formed in software having a secondary encoded code decoding function to decode the secondary encoded code into the primary encoded code and a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data.
Moreover, the present invention provides a data decompression method including the following steps. A secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. A compressed playback player is decoded into a playback player formed in software having a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.
Furthermore, the present invention provides a method of decompressing a secondary encoded code and a compressed playback player. The method includes the following steps. The secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. The compressed playback player is decoded into a playback player formed in software having a secondary encoded code decoding function to decode the secondary encoded code into the primary encoded code and a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.
Further more, the present invention provides a decompression method including the following steps. A combined code is separated into a lyric data and a secondary encoded code. The secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. A compressed playback player is decoded into a playback player formed in software having a secondary encoded code decoding function to decode the secondary encoded code into the primary encoded code and a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.
Moreover, the present invention provides a method of decompressing a combined code of a lyric data and a secondary encoded code, and also decompressing a compressed playback player. The method includes the following steps. The combined code is separated into the lyric data and the secondary encoded code. The secondary encoded code is decoded into a primary encoded code of music-performance data in which at least note-number data, musical note-velocity data, musical note-length data and other necessary data are arranged in different data fields. The compressed playback player is decoded into a playback player formed in software having a secondary encoded code decoding function to decode the secondary encoded code into the primary encoded code and a primary encoded code decoding function to decode the primary encoded code into the data arranged in the different data fields for reproducing the music-performance data. The primary encoded code is decoded by the playback player, thus reproducing the music-performance data.